Electric motor



(No Model.)

. H. E. WALTER.

ELECTRIC MOTOR.

No. 422,556. v Patented Mar. 4, 1890.

Snow wow '4. mm W Imc.

UNITED STATES PATENT Orrlcn.

HENRY E. ALTER, OF SGHENEC TADY, NEXV YORK.

ELECTRIC MOTOR.

SPECIFICATION forming part of Letters Patent No. 422,556, dated March 4, 1890. Application filed May 16, 1889- Serial No. 311,045. (No model.)

certain new and useful Improvement in Elec-' tric Motors, of which the following is a specification.

This invention relates to electro-dynamic motors which are arranged to be controlled from a distant point, as from a central generating-station, and my object is to provide simple and eflfective means for starting such motors, so that the currentshall not pass through the armature-coils until the fieldnnagnet is charged, whereby injury to the armature or excessive sparking from the passage of current when the field is not energized is avoided. In accomplishing this I make use of a switch for the armature-circuit whose operation is controlled by a magnet energized by the current, such switch being constructed or provided with means for retarding its movement, so that it will not act to close the armature circuit until the field-magnet issufiiciently charged. I prefer to make use of the attraction of the field-magnet itself for operating the switch.

My invention is illustrate'dcin the accompanying drawings, in which Figure 1 is a view in elevation of an electrodynamic motor provided with my invention, the circuit-connections being shown in diagram and the magnetic device attached to the field-magnet being in vertical section; and Fig. 2 is a diagram illustrating the use of a magnet other than the field-magnet.

A is the armature of the motor, and B B are the pole-pieces of its field-magnet, of which 0 is the yoke or keeper. D represents a generator supplying current to this motor, and also to other motors or translating devices. A circuit 1 2 extends from the generator D, and in such circuit is placed a switch E, by closing which the circuit is closed to the motor and the same is started. The motor is in a multiple'arc circuit 3 4, the field and armature.

being in shunt relation to each other. The

the blade 5 of a suitable switch. This switch for closing the armature-circuit consists of a lever F, pivoted at c, and connected at its outer endwith a vertical arm G, at whose lower end is a U-shaped iron armature or movable core H. Upon each of the polepieces of the fieldanaguet is fixed a sleeve (1, made of iron and open at both ends, and within each sleeve d is placed a brass or other non-magnetic sleeve 6, which is open at the top and closed at the bottom, where it rests on the pole pieces. The branches of the U- shaped armature H are arranged to slide in and out of the brass sleeves e. In the drawings the parts are shown with the armature H in itslowest position and the switch I) closed. Before i the motor is started, however, the switch b is open and the armature His raised to the top of the sleeve 6. When current is supplied to the motor by starting the generator D or by closing the switch E, the field magnet of the motor becomes energized and the attraction of the iron sleeves (Z, which form part of the pole-pieces of the field-magnet, is exerted upon the armature H and draws the same down, raising the switchplate I) and closing circuit to the armature be.

tween the plates at a. A spring K is provided for retracting the switch and opening the armature- -circuit when the supply of current is cut off by stopping the generator or opening the switch E. The use of the brass sleeves e, projecting above the hollow magnets (Z, permits a long movement of the parts, which. increases the simplicity in construction of the apparatus, and the tension of the spring K is so adjusted that the switch does not close the armature circuit until the field is sufficiently charged to prevent the danger or inconvenience which would otherwise arise in starting. This a'rrangement of a hollow magnet and the internal non-magnetic sleeve may evidently be employed for other purposes where it is desired to obtain a gradual movement over a long distance by magnetic attractiom Instead of the arrangement just described that shown in Fig. 2 may be employed. The magnet L is energized by a separate multiple arc circuit 9 10, when the switch E is closed, and such magnet draws down an armature f, which carries a switch-lever g for closing cir cuit at a a, the movement of the switch and armature being retarded by dash-pot 72, so that the circuit is not closed until the fieldmagnet is sufficiently energized.

iVhile I have described my invention with reference to simple electro-dynamic motors, it is evident that it is also adapted for use with rotating or continuous current-transformers for the purpose of preventing the passage of current through their armaturecoils before the field-magnet is charged, and in referring to motors in the claims I intend to include not only the simple electro-dynamic motor shown, but also continuous current transformers or combined. generators and motors.

lVhat I claim is 1. The combination, with an electric motor, of a switch for opening and closing its armature-circuit controlled by the attraction of its field-magnet, substantially as set forth.

3. The combination, with an electric motor, of a switch for opening and closing its armature-circuit, and a magnet in a constantlyclosed circuit for operating said switch, said switch having a retarded movement, so that the armature-circuit is not closed until after the field-magnetof the motor is energized, substantially as set forth.

3. The combination, with an electric motor, of a switch for its armature circuit and a magnetic body attached to said switch and placed in proximity to the poles of the field-magnet of the motor, substantially as set forth.

l. The combination, with an electric motor,

of a hollow iron sleeve attached to a polepiece of said motor, a magnetic core movable in said sleeve, and a switchfor the armaturecircuit of the motor attached to said core, substantially as set forth.

5. The combination, with an electric motor, of a hollow iron sleeve attached to the polepiece of said motor, a non-magnetic sleeve within the same, a movable magnetic core, and a switch for the armature-circuit attached to said core, substantially as set forth.

6. The combination, with an electric motor, of a switch for opening and closing its armaturecircuit, a constantly-closed field-circuit, and a magnet energized by the current in said ficld-circuit for operating said switch, said switch having a retarded movement, so that the armature-circuit is not closed until after the field-magnet of the motor is energized, substantially as set forth.

This specification signed and witnessed this 10th day of May, 1880.

HENRY E. \VALTER.

Witnesses:

\VILLIAM PELZER, D. It. DnisooLL. 

